import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

/**
 * Creater with IntelliJ IDEA.
 * Description:
 * User: 86152
 * Dae: 2022-07-31
 * Time: 19:03
 */
public class demo1 {
    public static void main(String[] args) {
        synchronized (demo1.class) {
            synchronized (demo1.class) {

            }
        }
    }
}
